import numpy as np

dt_student = np.dtype([("name", "S20"), ("age", np.int8), ("marks", "f4")])
a = np.array([("lilisi", 18, 80.0), ("Jack", 19, 92.5)], dtype=dt_student)
print(dt_student)
print(a)
'''
[('name', 'S20'), ('age', 'i1'), ('marks', '<f4')]
[(b'lilisi', 18, 80. ) (b'Jack', 19, 92.5)]
'''

print(a[0]); '''(b'lilisi', 18, 80.)'''
print(a["name"]); '''[b'lilisi' b'Jack']'''
print(a["age"]); '''[18 19]'''
